Development of highly sensitive temperature microsensors for localized measurements

This paper presents the design, fabrication and characterization of temperature microsensors based on Resistance Temperature Detectors (RTDs) with a meander-shaped geometry. Numerical simulations were performed for studying the sensitivity of the RTDs according to their windings numbers as well as for optimizing their layout. These RTDs were fabricated using well-established microfabrication and photolithographic techniques. The fabricated sensors feature high sensitivity (0.3542 mV/°C), linearity and reproducibility in a temperature range of 35 to 45 °C. Additionally, each sensor has a small size with a strong potential for their integration in microfluidic devices, as organ-on-a-chip, allowing the possibility for in-situ monitoring the physiochemical properties of the cellular microenvironment.This work is the result of the project NORTE-01-0145-FEDER-029394, RTChip4Theranostics, and was supported by Programa Operacional Regional do Norte–Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (FEDER) and by Fundação para a Ciência e Tecnologia (FCT), IP, project reference PTDC/EMD-EMD/29394/2017. The authors also acknowledge the partial financial support by the projects UIDB/04436/2020 and UIDP/04436/2020

Numerical and experimental investigations on micromixers geometries for high ratio flow rates

The micromixers presented here were designed to be implemented into a pH lab-on-a-chip (LOC) with a flow rate ratio of 19:1. The studied micromixers are based on passive mixing and planar geometries, which makes them easy to fabricate and integrate in microfluidic devices. Numerical simulations in COMSOL and experimental results are in good agreement and show excellent mixing performance for all tested micromixers. The study of micromixers performance with such a high ratio of the inlets flow rate has not yet been found in state-of-the-art, and, for that reason, this work might represent an important contribution in the field of micromixers when high disparity in the inlets flow rate are needed, as well as for further integration into the seawater pH LOC.This work was co-financed by Programa Operacional Regional do Norte (NORTE2020), through Fundo Europeu de Desenvolvimento Regional (FEDER), Project NORTE-01-0145-FEDER-000032 – NextSea and by project NORTE-01-0145-FEDER-029394, supported by NORTE2020, under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and by Fundação para a Ciência e Tecnologia (FCT), IP, project PTDC/EMD-EMD/29394/2017